Radio antenna



June 23, 1936.

A. MASSEY ET AL RADIO ANTENNA men/Lave:

Filed Aug. 9, 1934 INVENTORS Mmsafy HE/VAPY H222. /0/(.

BY JV/f/VEJ-S.

ATTORNEYS,

Patented June 23, 1936 UNITED- STATES PATENT V OFFICE 2,045,398 RADIOANTENNA Andrew Massey and Henry Hulick, Raleigh, N. C.

Application August 9, 1934, Serial No. 739,086 4 Claims. (01. 250 11)This invention relates to improvements in radio antenna:andvhasparticular reference to an apparatus for reflecting radiofrequency energy from an emitter in alldirections parallel to thesurface of the earth.

In the sending out of radio frequency energy by-the conventionalform ofantenna, much-of the energy emitted travels in a skyward direction andis of practically no use in commercial radio broadcasting. Themainobject of this invention is to reflect the radiation of the radiofrequency energy from the emitter in such direction as to travelparallel to, and at a constant distance above the earths surface. Thismethod of transmission eliminates all angular radiation and converts allthe transmitted energy into ground wave where it will create amostsatisfactory service area with minimum interference at a distance.

Another feature of the invention resides in a radio antenna whichincludes a cupped emitter;

Figure 1 is a diagrammatic view illustratingthe invention partly in sideelevation and partly in section.

Figure 2 is a view similar to Figure 1, but showing the parts inreversed position.

Referring to the drawing by reference characters, the numeral l0designates a conical diverter, the outer deflecting inclined surfaces llof which are of a 45 degree angle and of any suitable metal such assteel, copper, or aluminum. In Figure 1 of the drawing, the flat base l2of the diverter is shown as resting 'upon the earths surface A and theapex points skyward.

Supported above the top or apex of the conical diverter and in verticalaxial alinement therewith is a hemispherical shaped bafiie and reflector[3, the walls of which are concavo-convex with the open side thereoffacing away from the conical diverter.

Supported above the baffle I3 is a paraboloid reflector I4, the axis ofwhich is in vertical alinement with the vertical axis of the diverter l0and baffle l3 while the circumference of the same is the same orapproximately the same as the base l2 of the diverter Ill. The reflectorI4 is constructed of any suitable metal such as steel, cop-- per oraluminum and is concavo-convex with the concave side facing the conicaldiverter l0. The peripheraledge of the parabolical reflector I4 is onthe same plane as the, circumferential edge of the hemispherical bafflei3 for a purpose to be presently explained.

Mounted centrally of the hemispherical shaped bafiie I3 is aradio'frequency energy radiator or emitter I5, which may be in the formof a solenoid with the windings of the coils extending equal distancesfrom opposite sides of the axial center of the hemispherical baffle 13.

From the description thus far,.it will be under stood that the diverterI0, hemispherical reflector baffle I3, parabolic reflector I 4, andemitter I5 are arranged in vertical axial alinement with the bafiieinterposed between the diverter and the parabolic reflector, while theemitter is cupped on the diverter side by the hemispherical baffle 53.

In practice, the radio frequency energy discharged by the radiator oremitter i5 is transmitted radially, the baffle 13 preventing the directtransmission of the energy to the conical di verter,.and reflecting themupwardly toward the parabolic reflector M, it being noted that thebaffle is relatively small in diameter in compari' son with the diameterof the parabolic reflector I4 and the base of conical diverter it. Theoutwardly and upwardly diverted radio frequency energy shown by thelines I6 directly strike the curved reflecting surfaces of the parabolicreflector at an angle and are reflected with those transmitted from thereflector l3 in a downward vertical direction shown by the lines I! intothe 3 path of the upwardly converging walls ll of the conical diverterl0. After striking the upwardly inclined walls of the diverter, theradio frequency l4, thence downwardly upon the diverter l0, and

is reflected from the diverter III in a direction to travel parallel toand at a constant distance above the earths surface. This eliminates allangular radiation and converts all the transmitted radio frequencyenergy into ground wave where it will create a most satisfactory servicearea with minimum interference at a distance.

In Figure 1 of the drawing, we have illustrated the apparatus with thebase l2 of the cone rest-' ing upon the earths surface and the otherparts supported thereabove. However, the entire structure may bereversed 180 degrees, as shown in Figure 2, so that the convex side ofthe parabolic reflector rests upon the earths surface while the base ofthe conical diverter is at the top. The same result is obtained so faras the transmission of the radio frequency energy is concerned, but thedirection of reflection from the emitter I5 and reflector I3 isdownwardly while the reflection from the parabolic reflector is upwardlyonto the. elevated conical diverter In. In this position the groundwaves are transmitted on a higher level than that shown in Figure 1. I

While we have shown and described what we consider to be the preferredembodiment of our invention, it will be appreciated thatv the parts.

have been shown more or less diagrammatic and we do not wish to restrictourselves to various specific details of construction, but that suchalterations and changes as come within the scope of the appended claimsmay be resorted to if desired.

Having thus described the invention, what weclaim as new and desire tosecure by Letters Patentof the-United States, is:-

1. A radio antenna comprising in combination, a conical diverter, aparabolic reflector, said conical diverter and parabolic reflector beingarranged in superimposed relation and with their center axes in verticalalinement, a radio frequency energy emitter interposed between saidconical diverter and said parabolic reflector, and

a hemispherical baflie interposed between the.

onto the inclined surfaces of said conical diverter, and deflectedradially and horizontally therefrom parallel to the earths surface.

3. A radio antenna, comprising in combination, a conical diverter, aparabolic reflector, a relatively small hemispherical bafile interposedbetween said conical diverter and said parabolic reflector and a radiofrequency emitter positioned axially with respectto the bafile, saidconical diverter, parabolic reflector and baflle beingarranged invertical axial alinement, said baffle and parabolic reflector havingtheir peripheral edges on a horizontal plane to prevent radiation ofwaves from the emitter without striking either the baffle or thereflector and said bafile and reflector further being arranged withtheir concaved faces opposed so as to concentrate all of the waves fromthe emitter against the inclined Walls of the'conical'di'verter fordeflection radially and horizontally therefrom.

4. A radio antenna comprising in combination, a conical diverter, aparabolic reflector, a relatively small hemispherical baffle interposedIcetween said conical" d-iverter and said parabolic reflector; and aradio frequency emitter positioned axially with respect to the bafile,said conical diverter, parabolic reflector and baffie being arranged invertical axial alinement, and said bafile and parabolic reflector havingtheir peripheral edges on a horizontal plane so as to prevent radiationof waves from the emitter without striking either the baiile or thereflector.

' ANDREW MASSEY.

HENRY HULICK.

